1. Field of the Invention
The present invention relates to a tire handling system which is adapted to automatically perform a series of operations including sorting of tires conveyed from a production or inspection line according to types or sizes of the tires by means of a sorting device, stacking of the sorted tires by means of a stacking device, and shelving of the stacks of tires in frame pallets.
More particularly, the invention is concerned with an automatic tire supplying device adapted for supplying the stacking device of the handling system with the tires sorted by the sorting device incorporated in the same system, and a tire shelving device which can automatically shelve the stacks of the tires.
The invention is also concerned with an automatic tire inverting device incorporated in the tire handling system and capable of inverting the tires which are to be delivered to the stacking device.
2. Description of the Prior Art
Hitherto, the supply of tires to a stacking device has been conducted by conveying tires in a one-by-one fashion towards the stacking device by means of a conveyor, stopping a tire when it has reached a position near the stacking device, and manually conveying the tire one by one to the stacking device. In another known tire supplying system, a tire stopping device and a conveying device for conveying the stopped tire one by one are used in combination.
The supply of the tire relying upon the manual work suffers from an impractically low efficiency of the work, as well as a huge labour cost, due to the necessity for much human labour. On the other hand, the known system which makes use of a combination of the tire stopping device and the tire conveying device requires a complicated mechanism for clamping and conveying the tire one by one, as well as a large installation space for such devices and mechanism. In addition, a complicated control is required for operating both the tire stopping device and the tire conveying device smoothly in a timed relation.
The shelving of the stack of tires has been conducted manually by placing the stack of tires in a frame pallet. In some cases, a fork lift with clamp arms capable of clamping the stack of tires, or a power-driven roller conveyor capable of clamping the tire stack at upper and lower sides thereof is used. The method which makes use of a fork lift, not to mention the manual shelving, is inferior in the efficiency of the work, because it requires much human labour, as well as a high degree of skill. The method which employs the roller conveyor encounters a difficulty particularly when the stack of tires is placed at an offset from the center of the storage position on the frame pallet, although this method improves the efficiency appreciably.
In some cases, a special consideration has to be given to the orientation or posture of the tires to be stacked. Namely, when each of the tires to be stacked has a white belt or white characters on the side walls thereof, there is a fear that the white belt or white characters may be contaminated when the black other side wall of the adjacent tire is placed directly thereon. In such a case, it is necessary that every other tire be inverted so that the tires make contact at their white sides or black sides. The inversion of the tire also has relied upon manual labour and, hence, has suffered from low working efficiency and large labour cost.